Why ask this? Maybe they are? Maybe they aren't, and that's ok too.
On the other hand, building an entire company atop experimental software that might explode or cease to exist tomorrow seems so monumentally stupid that the inevitable business failure is the outcome they don't need, but so badly deserve.
All things come to an end. Why not ride the wave of a FOSS project, eg by offering support as a business. As long as you are prepared to pivot or close the business when it's no longer needed, why not?
It doesn't strike me as stupid.